1. Field of the Invention
The present invention relates to a retractable hypodermic safety syringe. In particular, the present invention relates to a safety syringe for completely encapsulating a needle after use to prevent accidental needlesticks or reuse of the needle.
2. Description of the Related Art
Healthcare workers in the United States suffer over a half million needlesticks each year. From these needlestick injuries healthcare workers contract HIV, become infected with hepatitis C and hepatitis B, and acquire such infectious diseases as tuberculosis, syphilis, malaria, herpes, diphtheria, gonorrhea, typhus and Rocky Mountain spotted fever.
Healthcare workers worldwide are concerned about accidental needlesticks resulting in life-threatening infections. Often, healthcare workers become patients after being injured by contaminated needles. These healthcare workers contract potentially deadly infections from needlestick injuries that are largely preventable.
Many methods and devices have been created to reduce accidental needlesticks by contaminated needles. An example of such a device is shown in U.S. Pat. No. 4,790,822. This patent discloses a retractable hypodermic safety syringe that retracts the used needle into the barrel of the syringe after use. A disadvantage of the design, however, was the expense and the difficulty of manufacture related to the molded internal parts of the syringe barrel, such as shoulders. Another disadvantage of this device was the inability to evacuate the entire contents of the cavity